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Biomedical subjects

T Van Joost

Publications and source records attributed to T Van Joost.

At least 19 recordsLinked to original sources
PubMed1999

Interferon-gamma-induced ICAM-1 and CD40 expression, complete lack of HLA-DR and CD80 (B7.1), and inconsistent HLA-ABC expression in basal cell carcinoma: a possible role for interleukin-10?

Basal cell carcinomas (BCCs) of the skin show varying degrees of peritumoural inflammatory infiltrate consisting mainly of T cells, but lack an effective T-cell-mediated immune response. This may be caused by the absence of the major histocompatibility complex (MHC) class I and II antigens, intercellular adhesion molecule-1 (ICAM-1), CD40 and CD80 (B7.1). Interferon-gamma (IFN-gamma) is known to induce or up-regulate their expression on epithelial cells, whereas interleukin-10 (IL-10) down-regulates their expression. The induction and up-regulation of HLA-ABC, HLA-DR, ICAM-1, CD40, and CD80 in BCC and normal skin from BCC patients were investigated in a culture system using recombinant human IFN-gamma (rHuIFN-gamma). The levels of IL-10 were determined in the supernatants after culture. The results showed that only ICAM-1 expression was significantly up-regulated on BCC cells. However, in the normal epidermis of BCC patients and in the epidermis overlying the tumour nests, significant up-regulation of ICAM-1, and CD40, and CD80 and slight up-regulation of HLA-DR were observed. No changes in HLA-ABC expression were observed in either normal skin or BCC. High levels of IL-10 were present in the supernatants of BCC biopsies after culture. It may be concluded that it is highly likely that the presence of IL-10 in BCC is directly or indirectly responsible for the complete lack of expression of HLA-DR, ICAM-1, CD40 and CD80 and the inconsistent expression of HLA-ABC on BCC cells in situ and may be a way of escaping immune survillance.

Adult↗
PubMed1996

Cutaneous pathology in primary erythermalgia.

Primary or idiopathic erythermalgia is characterized by recurrent, red, warm, and painful lower extremities. It arises at young age and persists throughout life because no treatment is available. We report the cutaneous pathology of affected skin lesions of three patients with primary erythermalgia. Biopsy specimens showed a mild perivascular mononuclear infiltrate, thickened blood vessel basement membranes, abundant perivascular edema, and moderate endothelial swelling. The thickened basal membrane of the blood vessels showed a laminar structure, and abundant perivascular edema and moderate endothelial cell swelling were evident. These histopathologic findings in primary erythermalgia appear to be nonspecific but allow diagnostic differentiation from erythromelalgia in which fibromuscular intimal proliferation and occlusive thrombi in the endarteriolar capillaries are apparent and from erythermalgia secondary to vasculitis. Histopathologic examination of affected skin lesions in patients with red, congested, warm, and painful burning extremities is a valuable tool in the diagnostic process.

Adolescent↗
PubMed1995

Efficacy and tolerability of multiple-dose SDZ IMM 125 in patients with severe psoriasis.

Although cyclosporin is effective in immunosuppression following organ transplantation and in the treatment of psoriasis, its use is limited by its side-effects, notably impaired renal function and hypertension. As SDZ IMM 125, a new derivative of the cyclosporin family, showed considerable immunosuppressive activity in experimental studies, with less effect on renal function, it was considered a potential successor to cyclosporin for both indications. In this multicentre, double-blind, placebo-controlled study, the efficacy and tolerability of 40, 100, 200 and 400 mg SDZ IMM 125 daily were studied in 59 patients with psoriasis. Patients were followed for a period of 5 weeks (4 weeks treatment, and 1 week post-treatment observation). A dose-dependent effect of SDZ IMM 125 was observed. A significant correlation was found between the dose of SDZ IMM 125 and changes in the sum of severity scores of three indicator plaques. There was a significant decrease in the body surface area affected by psoriasis in the 400-mg group (P < or = 0.01), whereas a decrease of the global psoriasis severity was observed in the 200-mg (P < or = 0.01) and the 400-mg groups (P < or = 0.001). No serious adverse events occurred during the 4 weeks of treatment. Three patients discontinued treatment because of adverse events (one sore throat, two influenza). Clinical adverse events were similar to those reported with cyclosporin, the most frequent being gastrointestinal disturbances. Estimation of renal function indices showed that increases from baseline values were dose-dependent, and appeared to be similar to those seen with cyclosporin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

The clinical effect of percutaneous histamine on allergic contact dermatitis elicited to fragrance mix.

Histamine (2-(4-imidazol)ethylamine) has been shown to downregulate cell-mediated reactions in vitro. However, the rôle of such downregulation in vivo has not yet extensively been studied in humans. In an attempt to gain more insight into this, we studied in vivo the effect of percutaneous histamine on an allergic contact reaction elicited to fragrance mix in 28 human volunteers with previously-known sensitization (patch tests) to this allergen. Histamine (0.1 mg/ml) was administered either via subcutaneous injections or by scratching at the site of patch tests to one concentration (8% pet.) of fragrance mix at different times. Histamine and control solution were administered immediately before patch testing (0 hours) or 2x at 0 and 24 h (after application). No significant differences were observed in the grade of delayed-type hypersensitivity reaction (DTHR) to fragrance mix (8% pet.) by visual reading when histamine or control solution was administered. This study did not exclude the possibility that histamine could inhibit DTHR to lower concentrations of the allergen used, and therefore additional in vivo studies are required.

Administration, Cutaneous↗
PubMed1995

Secondary erythermalgia associated with an autoimmune disorder of undetermined significance.

A 50-year-old female patient is described with an acquired, persisting and yet incurable erythermalgia featured by symmetric burning pain and red congestion of the extremities secondary to cutaneous vasculitis. A weakly positive antinuclear antibody titer and high titers of antibodies against gastric parietal mucosa cells pointed to an underlying but unclassifiable autoimmune disorder. It is concluded that histopathology of lesional skin contributes to the differential diagnosis of primary and secondary erythermalgia.

Antibodies, Antinuclear↗
PubMed1992

Verapamil-induced secondary erythermalgia.

A 59-year-old man developed red, swollen and warm feet accompanied by intermittent burning pain during treatment for cardiac failure and arrhythmias with several drugs including verapamil. The condition gradually worsened until there was persistent disabling burning pain and severe erythema and swelling of the feet. Aspirin and other analgesics were ineffective in relieving the discomfort. Histopathology of punch biopsies showed a mild perivascular mononuclear infiltrate and moderate perivascular oedema. Within 2 weeks of stopping verapamil the burning pain, erythema, and swelling of the feet had resolved. The clinical features and subsequent course are consistent with a diagnosis of erythermalgia secondary to verapamil.

Erythromelalgia↗
PubMed1992

Similarity between mycobacterial and human epidermal antigens.

Eight out of 17 mouse anti-Mycobacterium leprae monoclonal antibodies (MAb) were previously observed to react with human nerve and skin antigenic determinants in cryostat sections, using an indirect immunoperoxidase technique. These observations suggested that antigenic mimicry may be involved in the development of the clinical manifestations of leprosy. In the present study we have extended our earlier findings by investigating sera from leprosy patients and MAb using Western blot technique. It was observed that 30 sera and their corresponding F(ab')2 fragments from isolated IgG fractions of both tuberculoid and lepromatous patients reacted with 40-50 epidermal proteins of molecular weights (MW) ranging from 10 to 130 kDa. Sera from 14 controls, however, showed similar reactivity patterns. Absorption of nine patient and control sera with M. tuberculosis, M. marinum and M. kansasii resulted in the removal of several components of different MW in nine, four and three cases, respectively. No consistent differences between sera from leprosy patients and controls were observed. Four out of eight MAb against M. leprae which reacted with determinants in human epidermis and/or dermis in skin cryostat sections reacted with epidermal proteins of MW higher than 39 kDa in Western blot. Four MAb which showed reactivity in cryostat sections did not react in Western blot. Another four MAb did react with human epidermal proteins in Western blot but did not react in cryostat sections, indicating that the MAb were reacting with different epitopes in the two systems. Five MAb did not react with human epidermal proteins either in cryostat sections or in Western blot.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Benign persistent papular acantholytic and dyskeratotic eruption: a case report and review of the literature.

We report a case of a 35-year-old female with a persistent pruritic acantholytic and dyskeratotic eruption on the chest and vulva. The light and electron microscopic studies showed suprabasal epidermal clefting with acantholysis and dyskeratotic cells. We suggest that the most appropriate term for this case is that of benign persistent papular acantholytic and dyskeratotic eruption.

Adult↗
PubMed1990

Anti-Mycobacterium leprae monoclonal antibodies cross-react with human skin: an alternative explanation for the immune responses in leprosy.

A panel of 17 mouse monoclonal antibodies (MoAb) raised against Mycobacterium leprae (M. leprae) antigens was used to detect antigenic determinants in normal human skin. An indirect immunoperoxidase technique was used. Eight of the MoAb detected epidermal antigens similar to patterns well known for human sera. Five of these MoAb detected determinants in the dermis, too. These observations may indicate a certain degree of similarity between the antigenic determinants occurring in M. leprae and in the human host. We propose that such a similarity on the one hand may facilitate the survival of M. leprae in the human host when the antigens are not recognized as "non-self," a situation which seems to occur in lepromatous leprosy, when the patients' tissues are loaded with bacteria virtually without any immune response. On the other hand, M. leprae antigens which mimic host antigens may induce an auto-immune reaction against the host's own antigens, which could explain the immune reaction in tuberculoid leprosy and during a "reversal reaction" when M. leprae is not observed in the host tissues, but extensive granuloma formation occurs.

Animals↗
PubMed1989

Scanning electron microscopy comparing exclamation mark hairs in alopecia areata with normal hair fibres, mechanically broken by traction.

A scanning electron microscope was used to compare the distal ends of exclamation mark hairs from alopecia areata patients with the fracture surface of normal hair fibres, mechanically broken by traction. The exclamation mark hairs shows minimal damage to the cuticular cell pattern of the hair shaft. Where the cuticle was absent, cortex and medulla showed low-density features fanning out into a fringe-like structure at the distal ends. The fracture surfaces of normal hair fibres, mechanically broken by traction showed a markedly abnormal cuticular scale pattern, whereas the features of cortical and medullary tissue were normal. These morphological differences between the fracture surface of exclamation mark hairs and normal hair fibres, mechanically broken by traction, may enhance our understanding of the pathogenesis of alopecia areata.

Adult↗
PubMed1988

Low-dose cyclosporin A in severe psoriasis. A double-blind study.

Twenty patients with severe plaque psoriasis were selected to receive either low-dose cyclosporin A (CyA) or placebo (CyA vehicle) in a double-blind randomized trial at two centres. Within 4 weeks the mean reduction in the Psoriasis Area and Severity Index (PASI) in 10 patients receiving CyA (mean dose 5.5 mg/kg/day) differed significantly from the mean reduction in 10 patients receiving placebo. In eight patients given placebo a switch to CyA therapy resulted within 4 weeks in a mean reduction in PASI of 90%. In a total 15 out of 18 patients given CyA (83%) (mean dose 5.6 mg/kg/day) there was an improvement of greater than or equal to 75% in PASI within 4 weeks. In a 2-month tapering off phase a lower mean CyA dose (3 mg/kg/day) was effective in maintaining the reduced PASI scores in seven of nine patients. Four out of five CyA treated patients who entered a post-treatment observation phase had a relapse (PASI score greater than or equal to 50% of score at baseline) after a mean interval of 6.5 weeks. The most important side-effects were mild reversible hypertension in 5 of 18 patients (28%), and reversible elevated serum creatinine levels in 7 of 18 patients (39%). We consider that further studies are justified in severe chronic psoriasis to establish suitable regimens for maintenance of remission in psoriasis with low-doses of CyA or a combination of CyA with other anti-psoriatic agents.

Adult↗
PubMed1988

Primary cutaneous adenoid cystic carcinoma: case report, immunohistochemistry, and review of the literature.

We report a case of primary cutaneous adenoid cystic carcinoma in a 75-year-old man. Electron microscopy revealed similar features to those previously described in adenoid cystic carcinomas of salivary gland origin: wide intercellular spaces, pseudocysts containing replicated basement membrane-like material and true lumina lined by cytoplasmic membranes with numerous microvilli. Immunohistochemistry using antibodies to several cytoskeletal proteins (keratins and actin) indicated the presence of two epithelial tumour cell populations, one with the phenotype of myoepithelial cells, lining the pseudocysts and the periphery of the tumour fields, and another with the phenotype of acinar cells of the secretory coil of sweat glands. In addition, the tumour showed immunoreactivity for epithelial membrane antigen, but not carcinoembryonic antigen. A review of the literature on other cases of primary cutaneous adenoid cystic carcinoma showed that this tumour generally affects older patients with a female to male ratio of 4:1. The most common tumour site appears to be the scalp (40%), and the recurrence rate is 50%. Surgical treatment with extensive resection margins is recommended.

Adult↗
PubMed1987

Sensitization to methylenedianiline and para-structures.

A toxic-allergic skin reaction of the face, neck and arms due to accidental contact with methylenedianiline (syn: 4-4'-diaminodiphenylmethane) is reported in a cleaner at a chemical plant. Patch tests revealed sensitization to chemicals of the para-group. Earlier exposure to it was unlikely. Previous sensitization to related chemicals and possible cross-sensitization was considered to be the primary cause of the allergy and the clinical manifestations.

Adult↗
PubMed1986

Quinolones in the treatment of gonorrhoea and Chlamydia trachomatis infections.

123 Female patients suffering from uncomplicated urogenital gonorrhoea were treated with either 200 mg or 400 mg enoxacin. The cure rate in the 400 mg group was 100%; the cure rate in the 200 mg group was 95.7% 212 Male patients suffering from urethral gonorrhoea were treated with either 250 mg or 500 mg ciprofloxacin (one tablet). Cure rates in both groups were 100%. Post-gonococcal urethritis was observed in 31 out of 85 (36%) patients in the first, and 21 out of 79 (27%) in the second group. In a pilot study 42 male patients suffering from non-gonococcal urethritis were treated during one week with I g ciprofloxacin daily. In 22 patients Chlamydia trachomatis was isolated from the urethra: in 20 of these 22 cases Chlamydia trachomatis could not be cultured after treatment (cure rate 91%), but in 4 of these 20 cases (20%) and in 8 of the 20 Chlamydia trachomatis negative cases (40%) urine-sediment abnormalities were present after treatment.

Adolescent↗